“The science is unequivocal,” wrote the editors of over 200 international health journals in a simultaneously published call to action last month. What is needed is greater effort to meet the Paris climate accord target of keeping the global average temperature increase to well below 2°C — and preferably less than 1.5°C — above pre-industrial levels. Interventions from the healthcare sector can make a difference. Doctors can prescribe powder inhalers for asthma rather than those containing climate-active propellants, and avoid anaesthetic agents with big climate footprints such as desflurane. The Aga Khan Development Network has been building energy-efficient health facilities in low- and middle-income countries. The health of the planet and its human population are intimately entwined. In the fight against climate change, health workers are on the front line.